Heatmaps (v2.1.x - iOS)

The SDK allows users to display heatmaps on the map using the NMHeatmapManager class.

To add a heatmap to the map, retrieve an instance of this class using the NMSdkproperty heatmapManager , create a list of points, and pass it to one of the manager's methods:

-(NSUInteger)addHeatmapWithWeightedPoints:(NSArray <NMWeightedMapCoordinates *>*)weightedMapCoordinates;for weighted points (represented by an NSArray of NMWeightedMapCoordinates)
-(NSUInteger)addHeatmap:(NSArray <NMMapCoordinates *>*)mapCoordinates
for non-weighted points (represented by an NSArray of NMMapCoordinates).

Using non-weighted points is equivalent to using weighted points where each point is assigned a weight of 1.

It is also possible to pass a list of parameters as an object of the NMHeatmapParameters class. The following parameters can be set:

The radius of the heatmap elements (the default value is 20);
The opacity of the heatmap (the default value is 1.0);
The gradient to use for the heatmap;
A custom maximum intensity for the heatmap (if not set, it will be estimated automatically).

To change the data of an existing heatmap, call the

-(void)setDataWithHeatmapId:(NSUInteger)heatmapId mapCoordinates:(NSArray <NMMapCoordinates *>*)mapCoordinates

or

-(void)setDataWithHeatmapId:(NSUInteger)heatmapId weightedMapCoordinates:(NSArray <NMWeightedMapCoordinates *>*)weightedMapCoordinatesmethod.

To modify the parameters of an existing heatmap, use the

-(void)setDataWithHeatmapId:(NSUInteger)heatmapId parameters:(NMHeatmapParameters *)parameters

method, passing the identifier of the heatmap.

To remove a heatmap, call the -(void)removeHeatmapWithId:(NSUInteger)heatmapIdmethod.

Heatmap gradient

The color of the heatmap can be configured using a NSArray object with a list of NMHeatmapGradientValue. Each value is a pair consisting of a color and the intensity at which this color is applied.

The default gradient is defined as follows:

NSArray<NMHeatmapGradientValue *>* gradient = @[
[[NMHeatmapGradientValue alloc] initWithColor:[UIColor colorWithRed:0.4 green:0.9 blue:0.0 alpha:1.0] intensity:0.2],
[[NMHeatmapGradientValue alloc] initWithColor:[UIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:1.0] intensity:1.0]
];

When the first intensity value is greater than 0, the opacity of the corresponding color will be adjusted, leading to a smooth fading effect between the initial color of the gradient and the map.

Example:


NSArray<NMWeightedMapCoordinates *> *points = @[
[NMWeightedMapCoordinates weightedMapCoordinatesWithCoordinates:[NMMapCoordinates mapCoordinatesWithLatitude:19.07261881 longitude:72.883961] weight:1],
[NMWeightedMapCoordinates weightedMapCoordinatesWithCoordinates:[NMMapCoordinates mapCoordinatesWithLatitude:19.343497 longitude:72.883961] weight:1],
[NMWeightedMapCoordinates weightedMapCoordinatesWithCoordinates:[NMMapCoordinates mapCoordinatesWithLatitude:18.908447 longitude:73.328485] weight:1],
[NMWeightedMapCoordinates weightedMapCoordinatesWithCoordinates:[NMMapCoordinates mapCoordinatesWithLatitude:19.567605 longitude:74.202329] weight:1],
[NMWeightedMapCoordinates weightedMapCoordinatesWithCoordinates:[NMMapCoordinates mapCoordinatesWithLatitude:18.880478 longitude:72.936622] weight:4]
];

NMHeatmapParameters *parameters = [[NMHeatmapParameters alloc] init];
parameters.radius = 10;
parameters.opacity = 0.5;

NSUInteger heatmapId = [sdk.heatmapManager addHeatmapWithWeightedPoints:points parameters:parameters];

The resulting heatmap: